A storage system is a computer that provides storage service relating to the organization of data on writable persistent storage media, such as non-volatile memories and disks. The storage system may be configured to operate according to a client/server model of information delivery to thereby enable many clients (e.g., applications) to access the data served by the system. The storage system typically employs a storage architecture that serves the data in file system and block formats with random and streaming access patterns. Disks generally provide good streaming performance (e.g., reading of large sequential blocks or “track reads”) but do not perform well on random access (i.e., reading and writing of individual disk sectors). In other words, disks operate most efficiently in streaming or sequential mode, whereas small random block operations can substantially slow the performance of disks.
One way to improve performance of the storage architecture of the storage system is through the use of hybrid storage media, e.g., by intermixing relatively expensive electronic storage, such as solid-state devices (SSDs), with relatively inexpensive magnetic storage, e.g., such as hard disk drives (HDDs), to provide a total storage space of the system. Typically, users or administrators of such conventional storage systems identify and isolate frequently accessed (i.e., “hot”) data that could most benefit from being stored in SSDs, with the remaining data being stored on the HDDs. However, identification and isolation of such hot data is typically performed and enforced manually, thus requiring time-consuming levels of effort by the administrators.
In addition, the administrators of these conventional systems typically render decisions to configure the physical layout of the SSDs and HDDs to create one or more volumes, each of which has a logical arrangement of volume block number (vbn) storage space used to organize data. The administrators may then render decisions to employ static or fixed allocations of the data, e.g., the data associated with a first range of vbns resides in one group of storage based in the SSDs, while data associated with a second range of vbns resides in another group of storage based in HDDs. However, implementation of such fixed data allocation decisions is time-consuming and expensive, particularly when changes are made to the allocations.